Fillets producing fish (Pangasius hypophthalmus Sauvage, 1878 )
Habit and Habitat: Pangasius hypophthalmus is fresh water fish species. Mekong River fishery occupied most of that major fish species, Pangasius hypophthalmus is the largest and most important inland fisheries in the world. Pangasius hypophthalmus prolific spawner produce relatively large numbers of larvae that are easily harvested from the river and pond of Viet Nam, Thailand, Cambodia and Bangladesh also. P. hypophthalmus is a highly migratory riverine fish species that makes long-distance migrations.
Biological Characteristics of Pangasius hypophthalmus:
- Body latterly flattened long with no scales.
- Head is relatively smaller than the body.
- Mouth broad and contain small sharp teeth that are vornerine and palatal bones.
- Eyes place nearer to snout and relatively large.
- There are two pair of barbels upper side of head and nearer to the snout, lower barbels longer than the upper barbels.
- Pectoral, pelvic and dorsal fins dark grey or black. Dorsal fin rays contain six branched.
- Well-developed gill rakers.
- Young fish have two black stripe along lateral line and below lateral line.
- Adults color uniformly grey and sometimes with greenish tint and sides silvery.
- Anal fin contains on middle a dark stripe, dark stripe is present of each caudal lobe.
Economic Importance: Pangasius hypophthalmus is widely fillet producing fish species all over Asian countries like Viet Nam Thailand, Indonesia, Malaysia, Cambodia, Bangladesh, China and Lao Peoples Democratic Republic.
Diseases of Pangasius hypophthalmus: Despite large tonnages production with high densities large-scale disease outbreaks and mortality of Pangasius hypophthalmus seldom occur. The following diseases have been recorded:
Bacillary Necrosis of Pangasius (BNP) is caused by agent Bacterium Edwardsiella ictaluri with symptom Petechial haemorrhages on eyes and fin bases; white spots in the kidney, spleen and liver; some cellular necrosis that removed by antibiotic.
Motile Aeromonad Septicaemia (MAS) is caused by agent Bacterium Aeromonas spp. (mainly A. hydrophila, A. sobria and A. caviae) with symptom Haemorrhages on eyes, body and fins; bloody ascites in the peritoneum, leading to swollen belly that removed by Improved water quality and nutrition; antibiotics.
Jaundice disease with symptom yellowish of the flesh removed by improved husbandry and nutrition; antibiotics.
Fingerling stage can be attacked by Parasitic infections named Ichthyophthirius and Trichodina at the and are usually treated with 15-20 ppt of formalin for 30 minutes with aeration before water exchange. The fluke worm (Clonorchis sinensis) can infect the liver during the grow-out stage. Prevention by thorough pond preparation is essential because treatment with drugs takes time and has a low efficacy.